The U.S. Treasury Department says it has identified 39 companies and people who laundered money for Mexico's notorious Arellano Felix drug cartel.

Treasury officials said Wednesday the group laundered more than $120 million in illicit proceeds from the sale of narcotics over a three-year period.

The money laundering operation allegedly involved currency exchange houses in the northern Mexican city of Tijuana, where the cartel is based.

The Treasury Department said it has added the names of the companies and people involved to a list of drug kingpins, meaning U.S. nationals and residents are barred from having business and financial ties with them.

The Arellano Felix cartel is one of Mexico's most-feared drug trafficking organizations.